However, I still had hope for reviving the WR850G, so today I decided to “debrick” it, ie. to force a firmware flash in order to restore the router to working order. I found a guide on doing this, but I only ended up not using it at all. I did, however, get the case open, which was like trying to pry something from the hands of Hercules, but this was not required to debrick the router! Here is what I did…

1. Download Motorola WR850G 4.03 firmware and extract it to a location on your hard drive. There should be a .TRX file in there. That’s the firmware file!

2. Download the Linksys TFTP Utility and save it to a location on your hard drive. It’s a standalone program.

3. Now connect the WR850G to your PC via ethernet. I would suggest you disconnect any other routers. You do not have to connect your WR850G to your modem via the WAN port.

4. For the NIC on the PC connected to the WR850G assign static IPs. For the NIC’s IP use 192.168.10.5, use a subnet mask of 255.255.255.0 (default), use a Default Gateway of 192.168.10.1 and a Preferred DNS of 192.168.10.1.

5. Power on the WR850G, wait for a minute or so and then press and hold the reset button for about 15 seconds. This may or may not help in the process.

6. Execute the TFTP Utility and fill in the necessary information. Your server is 192.168.10.1 (the same as our Default Gateway and Preferred DNS). Browse for the firmware .TRX file that you extracted earlier for ‘File’. If your router is completely bricked, ie. you couldn’t even log into it via the web interface, then you may not require to enter a password. In my case I didn’t need one. Click “Upgrade” to start the flashing process and cross your fingers.

7. If the upgrade was successful then you should get a green light and a “Successful” notice. This may take some time to appear and your router lights will flash for a while. Give it some time (approx. 2 mins.) even after a successful flash.

8. Try logging into the router through your web browser by going to the address http://192.168.10.1. If you get a login screen then start rejoicing! For the username use admin and for the password use motorola. Make your necessary customizations. If you want to start fresh you can restore to factory defaults before continuing.

9. Motorola has released an upgraded firmware since the v4.03 firmware for the WR850G. The latest version (to date of this article) is the v6.1.4 firmware. You must extract the files in the archive in order to retrieve the .TRX firmware file. DO NOT FLASH WITH THE COMPRESSED ARCHIVE! You can go through the web interface and upgrade the firmware as you normally would by locating the new .TRX firmware file. After a successful flash you will need to restart the router.

You’re finished!

I’ve noticed that Motorola has changed the web interface a lot since the v4.03 firmware for the WR850G.

Well, now I have a good-as-new working WR850G wireless router and I didn’t have to meddle with jumping wires or anything! Hope it stays that way for a long time to come!

2 Responses

I’m doing this on a Mac. I have Boot Camp and tried following the directions on Win 7, but I can’t get to the screen where you enter in the static IPs. I went to device manager and found my network adapter, but I can’t get to the screen you got to enter in DNS info., etc.